Light pencil



Feb. 17, 1942. F. w. KIDDER' LIGHTV PENCL Filed Jan. 29, 1940 BY i l 1N VENTOR l TTORNE Y.

Patented Feb. 17, 1942 UNITED. STATES lPATENT OFFICE .2,273,360 I Amdrrr PENCIL Frank W. Kidder, Los Angeles, Calif.

- Application January 29, 1940, serial No. '316,093

5 Claims?A (Cl. S35-L1) This invention relates to light pencils, and 'hals iur an object the' provision of a device Which-is useful in the correctionofnegativesor unprinted positives by hand in such a way as to modify the relative printing values of certain areas of an image. The invention is particularly adaptable for X-ray use where -X-ray plates have been made of given areas of the human body, such as bone fractures, and it is desired to render visible more detail than is readily discernible by inspection of the negative or unprinted positive.

A further object of the inventionis the provision of a device adapted to be manipulated by hand, and which is so constructed that it can 'be used in a solution.

The term .Working up as used in photography includes any method-of correcting negatives or A imprinted positives to overcomefaults or to im- -prove the rendering, reducing the contrast, to obtain details of the image, or to subdue too pronounced details. l

Further-objects include a device which is simple of structure, easy to handle, and produces superior results. 1

Otherobjects of the invention will appear as of parts, members and features, all as shown in a certain embodiment in the accompanying drawing, described generally, and morev particularly pointed out in the claims.

In the drawing:

Figure 1 is a perspective` View of the improved light pencil in position of use,

Figure 2 is al longitudinal sectional view of the light pencil,

Figure 3 is a sectional View on the linev 3-3 of Figure 2, and

Figure 4 is a fragmentary detail of certain portions of the light pencil.

Referring now with particularity to the drawing, lt/he improved light pencil is designated as an entirety and in one embodiment by I, and the same includes an elongated tubular housing 0r -casing 2, screw-threaded at both ends as shown at 3 and 4. Concentric within the casing or body 2 is a tubing 5, one end .being annularly inturned-or flanged, as shown at. 6. A knurled knob 1 having a shank portion 8'is secured tok the part 6 so that turning of the knob produces rotation of the tube 5 relativel to the tubular housing or casing 2. The construction -is such that the medium of a cap nut 3 in threaded engagement With the' threads 3.l This cap nut surrounds the shank 3. The knurled knob 'I is formed with central concentric bores ill and Ii,

lthe bore il being the one of greatest diameter,

and a contact member i2 has its stem i3 passed through both bores i0 and iI, terminating in a thepartsare readily held in assemblage through 55 knurled head I4. Within the bore Ii and surrounding the stem i3 is a coil spring I5 normally urging the contact member in one direction, towit, outwardly. The stem is formed 'with an annular groove I3 and a spring-pressed detent I'I in the shank of the knurled knob may be received within said annular groove when the stem is moved inwardly of said knob.

The tubular 'housing 2 has secured to the threads 4 thereof a tip I3. The outer surface of the tip is conical in part whereas the central bore I9 is substantially of uniform diameter. The tip is shouldered at 2li. A glass disc 2i having annular gaskets positioned on opposite sides thereof, as shown at 22 and 23, is positioned within the tip and rests upon the shoulder 20.

The tubular housing or casing 2 is formed with a pair of diametrically positioned bayonet slots 24 and 25. An annular plate 26 provided with diametrically disposed pins 21 and 28 is adapted to have the p ins thereof received within said bayonet slots for locking the said plate in position. This plate is provided with an annular flange 29 and an annular disc 30 may rest upon the top surface of said iiange 29 so as to provide as between the plates 26 and 30 an annular space 3|. The plate 30 is formed with a series of radial grooves 32 and with a rim notch 33. The tube 5 is provided with a depending portion 34 for reception in saidnotch 33. Interposed in the space 3| is an iris, designated generally as 35, and the leaves of the iris are provided with pins designated generally as 3G, which pins are positioned in the said radial slots 32, see Figure 3.

Adapted for placement within the connes of the tube 5 are one or more dry cell batteries 31. As is customary, thernegative terminal of the dry cell battery is surrounded with a paper covering 3 8. Normally urging the cells in one direction is a coil spring 39 interposed between the flange 6 and an insulation 40 adapted to bear against the base of one of the cells. This insulation is provided With a central opening 4I whereby the contact I2 may engage the base of the cell. The positive terminal 42 of one of the cells is positioned so as to .engage a terminal of an electric bulb 43. This electric bulb is held within a screw socket 44 of a member 45. This member 45 condisc 2| will remain within the tip and that the members 28, 30 and 35 may be removed by rotating the plate 26 so that the pins are released from the bayonet slots 24 and 25, whereupon the member 45 may be removed from within the tube 5 which, of course, allows the-batteries to be re- A moved from the tube 5. When the parts are in assemblage, as shown in Figure 2, the iris is readily manipulated by holding the tubular housing 2 with one hand while turning the knurled knob 1 with the fingers of the other hand. It will be observed that the knurled knob is directly connected through the medium of its shank with the tube 5 and'fthat this tube 5 has a portion 34 thereof received within the notch 33. Hence, rotation of the tube 5 produces rotation of the disc 30 and causes the pins 36 to move within the confines of the radial slots 32 Hence, the iris is actuated so as to open or close the same any desired amount.

The operation, uses and advantages of the invention are as follows:

If it is desired to work up a negative or unprinted positive, the finger may depress the ,contact I2 so as to permit the detent to enter the groove I6 and hold the contact against the base of the battery. When this occurs, an electrical circuit will be completed to the terminals of the electric light bulb. 'ght from said bulb will pass through the oper of the iris and the glass plate 2| and out filly through the tip as, for instance, indicatedL by the dotted lines of Figure 1 at 46. The size of the beam is readily regulated by rotation of the knurled knob I which will enlarge or close the iris opening as desired. By pulling upwardly upon the member I4, contact` with the dry cell is broken. As the glass member 2| is surrounded on both sides by gaskets, it is evident that the device is uid tight and the same may be utilized within a solution. This is important at times in the proper development of X-ray plates when it is desired to produce contrast or reduce contrast in certain areas. In any event, the device readily allows a working up" of the negative or unprinted positive.

To those skilled in the art, a device such as described is of value. The size of the beam of light is readily controlled by operating the iris and for this reason, the external diameter of the tip I3 is maintained substantially uniform.

It is evident that the light emitted is actinic.

I claim:

1. A device of the character described including a tubular casing, a. tube substantially coextensive in length with the casing and adapted to contain a battery, said tube being rotatably mounted within the casing and having an loperating member projecting from the rear end thereof, a source of light within the tube, an iris forwardly of said light, an annular control plate operatively connected with the iris and having a peripheral notch, and a depending portion on the end of said tube received in said notch.

2. A device of. the character described including a tubular casing, a tube substantially coextensive in length with the casing and adapted to contain a battery, said tube being rotatably mounted within the casing and having an operating member projecting from the rear end thereof, a source of light within the tube, a removable annular plate normally closing the forward end of the casing, a removable annular control plate normally closing the forward end of the tube and being rotatable therewith, an iris disposed between said annular plates and operatively connected with said control plate for the opening and closing of the iris, a tubular tip threaded on the forward end of the casing and having an internal shoulder, a lens having a marginal portion disposed between said shoulder and the forward end of the casing, and annular gaskets on opposite sides of the lens and respectively in sealing engagement with said shoulder and the forward end of the casing.

3. A device of the character described including a tubular casing, a tube substantially coextensive in length with the casing and adapted to contain a battery, said tube being rotatably mounted within the casing, a source of light within the tube, an annular plate extending across the forward end of the casing, an annular control plate extending across the forward end of the tube and being rotatable therewith, an iris disposed between said annular plates and operatively connected with said control plate for the opening and closing of the iris, a tubular tip threaded on the forward end ofthe casing and having an internal shoulder, a lens having a marginal portion disposed between said shoulder and the forward end of the casing, and annular gaskets on opposite sides of the lens and respectively in sealing engagement with said shoulder and the forward end of the casing.

4. A device of the character described` including a tubular easing, a tube substantially coextensive in length with the casing and adapted to contain a battery, said tube being rotatably mounted within the casing, a source of light within the tube, an annular plate positioned in the forward end of the casing, an annular control plate positioned in the forward end of the tube and being rotatable therewith, an iris disposed between said annular plates and operatively connected with said control plate for the opening and closing of the iris, and a fluid tight lens closing th'e forward end of the casing.

5. A light pencil including a tubular casing, a tube substantially coextensive in length with the casing and adapted to contain a battery, said tube being rotatably mounted within the casing and having an operating member projecting from the rear end thereof, a source of light within said tube, and an iris adjacent the forward end of the tube and forwardly of said source of light andl controlled as to opening and closing thereof by rotation of said tube.

FRANK W. KIDDER. 

